This invention relates to a steering mechanism for use in conjunction with a wheelchair and, in particular, to a steering mechanism that allows the chair to be both controlled and propelled by an occupant having the normal responsive use of only one hand.
Oftentimes persons who are confined to a wheelchair have lost the use of one of their hands and possibly one of their legs through injury, a stroke or the like. As a result, it is extremely difficult, if not impossible, for this type of handicapped individual to both propel and maintain directional control of the wheelchair. Although the user may be able to propel the chair using one arm, steering the chair becomes a major problem.
As set forth in U.S. Pat. Nos. 3,017,199; 3,388,926 and 3,810,658, this particular problem has been long recognized in the art. In response thereto, steering devices that are controllable by the leg or foot of the chair occupant have been devised. These prior art devices, which operate quite well, nevertheless have some disadvantages associated therewith that limit their effectiveness. Typically, the steering mechanism provides little or no mechanical advantage to the user and, as a consequence, the user soon becomes tired or loses the strength needed to safely guide the chair. Similarly, in the event one of the chair's swivel casters, which is usually directly coupled to the steering mechanism, strikes an obstruction, the caster will be rapidly and sometimes violently turned from its intended path of travel. This uncontrolled turning motion is usually translated directly through the mechanism to the occupant's foot or leg and, particularly in the case of an infirm individual, can cause harm. The casters can also be turned in a position where the chair cannot be propelled or may even tip over. Lastly, many of the prior art steering devices involve relatively rigid mechanisms which prevent the chair from being folded for convenient storage, as for example in the user's automobile.